Abstract

Assessed as up to date: 2004/03/11

Background

Metabolic or mixed (metabolic and respiratory) acidosis are commonly encountered problems in the low birth weight (LBW) infant after delivery, and they may contribute to mortality and morbidity. Causes for the lactic acidosis are multiple and include maternal, placental and fetal factors. It is unclear whether metabolic acidaemia in the first 24 hours of life in LBW infants should be corrected by rapid infusion of alkali.

The main objective was to assess the short and long-term effects of the rapid correction of early (first 24 hours) metabolic acidaemia in LBW (<2500g birth weight) neonates.

Searches were undertaken of MEDLINE from February 2004 back to 1966 and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2004). The title and abstract of each retrieved study were examined to assess eligibility. If there was uncertainty, the full paper was examined.

Types of studies
All randomised controlled trials where short or long term effects of treatment with alkalising agents by rapid infusion were compared with placebo or no treatment, or where rapid infusion of alkalising agents was compared with slow infusion.

Types of participants
Newborn infants with birth weight <2500g and less than 24 hours of age with proven metabolic acidaemia (on arterial blood gas).

Types of interventions
Rapid correction of acidaemia with alkalising agents (sodium bicarbonate and/or THAM) given as a bolus over 5 minutes or less compared with either placebo, no intervention or slow infusion (>5 minutes).

Types of outcome measures
1) maximal oxygen requirement in first 24 hours
2) duration of oxygen therapy
3) need for and duration of assisted ventilation
4) intraventricular haemorrhage and/or periventricular leucomalacia
5) survival to discharge
6) long term survival (to 24 months of age)
7) neurological and developmental outcome at 24 months of age

Each reviewer assessed eligibility, trial quality and extracted data separately, then compared and resolved differences. Study authors were contacted for additional information if necessary.

No studies were found meeting the criteria for inclusion in this review.

There is no evidence available from randomised controlled trials to support or refute the rapid correction of metabolic acidaemia, in LBW infants in the first 24 hours of life, as compared with slow or no correction.

Author(s)

Kecskes Zsuzsoka, Davies Mark W

Summary

Rapid correction of early metabolic acidaemia in comparison with placebo, no intervention or slow correction in LBW infants

Plain language summary will be included with future update.

Reviewer's Conclusions

Implications for practice

There is no evidence available from randomised controlled trials to support or refute the rapid correction of metabolic acidosis, in LBW infants with metabolic acidosis in the first 24 hours of life, as compared with slow or no correction.

Implications for research

If rapid correction is thought to be a useful treatment in the correction of metabolic acidaemia then there is a need for studies, with a larger number of infants, to clarify whether there is any benefit from this treatment without significant harm. However, given the lack of evidence that any correction of metabolic acidaemia confers significant benefit without harm, it would probably be prudent to investigate whether any correction of metabolic acidaemia is beneficial before studying rapid correction. Any studies investigating the use of alkalising agents should include important clinical outcomes such as ventilatory parameters, mortality, IVH/PVL and neurodevelopmental outcome. Despite the apparent lack of benefit or detriment of rapid correction of metabolic acidosis, the potential hazards of this therapy should be appreciated. As caution is warranted as to the possibility of intraventricular bleeding after rapid injection of alkalising agents, this question may best be answered in animal studies first.